ISLAMABAD: The explosion occurred in the village of Danu Dandal in the Nagarparkar district of Tharparkar while a baby and other patients were being transferred between hospitals.
The blast reportedly triggered a fire that killed nine people, including hospital staff and local residents who were near the ambulance at the time.
Rescue teams rushed to the scene, and the five injured people were taken to a hospital in Karachi for treatment. They were reported to have sustained serious injuries.
Pakistani authorities have launched an investigation to establish the cause and circumstances of the explosion.
President Asif Ali Zardari expressed sorrow over the loss of life, extended his condolences to the families of the victims and wished the injured a speedy recovery.